The output is admittedly rather low, but that depends on the synth - if you
start the B3 it whollops out a fair old volume. Also historically some of
the filters would overdrive rather easily, so some of this was to contain
the levels.

If you are looking at independent synths there is a final ouput gain stage -
try it with -outgain 8 or 16. In the longer term the different synths need
to be normalised for a gain level. Perhaps I could make the outgain an
emulation option rather than an engine option? Try it out, if it works I
will recode some of it.

Regarding crashes - the most extensive work I have done here has been with
ALSA drivers, and there are some potential issues with Jack that could lead
to misbehaviour. To start with I don't deal with buffer size changes. If
they get smaller fine, but if they get bigger then there are potential
problems.